Factor XIII in chronic inflammatory bowel diseases.

Severe acute inflammation in chronic inflammatory bowel disease is associated with large wound areas and ulcerations that show spontaneous hemorrhage or marked friability. Therefore, an enormous potential of hemostasis and wound healing is required. Coagulation studies demonstrate a deficiency of factor XIII that is important for both clot formation and wound healing. Consequently, the substitution of factor XIII may be beneficial; the first case reports present favorable clinical results. In a prospective pilot study, we treated 12 patients with therapy-resistant ulcerative colitis. The colitis activity index (CAI) and the endoscopic score (ES) according to Rachmilewitz were elevated; all patients suffered from hematochezia. After substitution therapy with factor XIII concentrate (1,250 U/d) the stool frequency dropped and no further hematochezia was detected. The CAI and the ES declined highly significantly. Because of these encouraging results two placebo-controlled multicenter trials have been initiated. In the first study, patients with acute stage of ulcerative colitis associated with severe intestinal blood loss are treated with two different dosages of factor XIII concentrate (1,250 and 500 U/d, respectively) or placebo for 10 days. In the second trial, patients with therapy-resistant ulcerative colitis with a lack of remission in spite of a consequent therapy for 2 weeks are included; factor XIII concentrate or placebo is administered for 10 days. The aim of both trials is an end of intestinal bleeding and the fostering of a more effective wound-healing process.